Abstract: Roving residue is removed from roving-bobbin tubes returned from the ring-spinning machines to the roving frame and upon detection of residual roving, that tube which carries a residue is switched with a tube from a magazine containing residue-free tubes. A color sensor detects the color of the tube with the residue to be removed from the train and a tube of corresponding color is positioned at the changeover station of the magazine. The colors and positions of the tubes in the magazine can be stored in data storage or a color sensor can detect the color of the tube in the magazine at the changeover position.